Nowadays, a high power engine and increased fuel efficiency are required of an automobile or the like. Because of these requirements in performance as well as design, demand is becoming stronger for higher-performance and smaller-size parts including brakes clutches and so on. For example, requirements for a disk brake are that it be serviceable when exposed for a short time to much higher temperatures than before (e.g. maximum temperature of the cast iron rotor, about 900.degree. C.), that it should have anti-fade properties at such elevated temperatures from the viewpoint of safety, and that its life be long.
The limits of heat resistance of a friction material for use in disk brakes or clutches are governed mainly by the heat resistance of a binder resin contained therein. The service temperatures of the disk brakes, however, greatly surpass the limits of the heat resistance of conventional binder resins such as phenolic resins.
The proposals made as solutions to this problem were a friction material for a brake which was produced by hot-pressing a friction material containing a binder of bulk mesophase carbon at a temperature of 400.degree.-650.degree. C. followed by semi-carbonizing it (Japanese Laid-Open Patent Publication No. 219924/1988); and a method of treating the so obtained friction material for a brake at a temperature of 1050.degree.-1150.degree. C. under a hydrogen atmosphere (Japanese Laid-Open Patent Publication No. 310770/1988). The friction materials produced by these contrivances had good anti-fade properties, but were still problematical in terms of durability.